Paint stripping compositions and methods

ABSTRACT

The present invention relates to light and heat reactive paint or polymer stripping compositions preferably employing biodegradable components such as conjugated terpenes and related polyenes in combination with an alcohol such as a phenyl substituted benzyl alcohol for use in removing polymeric materials from substrates, in particular, cured paint from hard and/or flexible surfaces. The compositions avoid the use of methylene chloride, phenol, corrosives and caustics, methanol, toluol or acetone. Compositions according to the present invention preferably have flash points above about 49° C. (about 120° F.) and a pH which is preferably neutral. 
     Methods of stripping polymeric coatings from surfaces and methods of making these compositions are also described.

RELATED APPLICATIONS

This is a division of application Ser. No. 08/227,789, filed 14 Apr.1994, now U.S. Pat. No. 5,427,710, which is a continuation-in-part ofapplication Ser. No. 08/048,466, now U.S. Pat. No. 5,425,893, entitled"Photoreactive Paint Stripping Compositions and Methods", filed Apr. 14,1993.

FIELD OF THE INVENTION

The present invention relates to novel compositions and methods whichare useful for softening or stripping paint. More particularly andpreferably, the invention employs compositions which are generallyreactive to light or heat energy (UV, visible, infrared, convectionheat) and are substantially biodegradable, which remove paint and otherpolymeric coatings from flexible and inflexible surfaces.

BACKGROUND OF THE INVENTION

Present methods for the removal of polymeric substrates from surfacessuch as aircraft, railcars and aging steel structures such as bridges(which may include lead based paint), involve the use of abrasives,highly alkaline compositions or materials which exhibit a high degree oftoxicity and corrosiveness.

Typically, the method of choice is to sand blast the structure at highpressure. The process, however, produces airborne particulates,sometimes containing lead and silicates. Additionally, sand blastingexpands exponentially the mass of contaminant to be treated or disposed.

Alternatives to the use of sand blasting include the chemical strippers,which generally fall into one of two categories. Some strippers fallinto both. One category is the caustic removers, the other is solventbased removers. The caustic removers may be formulated as liquids orpaste compositions.

Stripping compositions containing strong corrosive agents, for example,phenol, in combination with methylene chloride and other substances arepresently in use for stripping commercial aircraft. When applied, thesecompositions cause the paint to swell and loosen from the grounding. Theouter coating is then scraped off by hand. This rather tedious procedurehas several drawbacks. First, the solvents used (in particular, phenoland methylene chloride) are highly toxic, caustic, deleterious and/orcarcinogenic. Second, safety regulations require workers to wearprotective clothing and gas masks, both of which must be disposed ofafter only a single use. A third drawback is that the flooring under theairplane must be fully covered to protect it from drippings andpenetration by the corresive agents. Fourth, the paint residue (whichmay amount to several tons of waste material from a single aircraft),clothing and floor covering must be specially disposed of as a toxicwaste at great expense.

OBJECT OF THE INVENTION

It is an object of the present invention to provide paint strippercompositions which are safe and effective to remove paint and otherpolymeric coatings in protective and decorative coatings on flexible andinflexible surfaces.

It is also an object of the present invention to provide compositionswhich are non-flammable and effective paint strippers and which avoidthe use of halogenated solvents, petroleum based aromatic compounds,ketones, methanol and alkali metal hydroxides.

It is an additional object of the present invention to provide strippingcompositions and methods for removing conventional polymeric coatingssuch as paints, coatings, nail polishes and the like, which utilizelacquers, varnishes, enamels, for example, drying oil type, alkyds, ordrying oil-alkyd modified enamels, epoxy esters, epoxy amides,amine-catalyzed epoxies, acrylics, polyurethanes and two part epoxyprimer/polyurethane top coats, among numerous others.

It is a further object of the present invention to provide a method ofstripping polymeric coatings using the compositions of the presentinvention to reduce the mass or volume of effluent generated in theprior art stripping processes.

It is still an additional object of the invention to provide a method ofstripping exterior polymeric coatings which facilitates separation ofremoved toxic coatings from the medium of removal without generatingadditional toxins than those already present in the coating to beremoved.

It is yet another object of the invention to provide a method of makingthe compositions of the present invention, especially those compositionswhich are thixotropic in character.

It is yet an additional object of the invention to provide compositionswhich can be applied by an airless spray system by forcing thecomposition through a nozzle of sufficient diameter under effectivepressure so that shear forces permit deposition of a composition havingsufficient viscosity and surface tension to adhere to vertical surfaces.

These and other objects of the invention may be readily gleaned from thedescription of the invention which follows.

BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to novel paint and polymeric coatingchemical strippers which preferably are reactive to light and/or heatenergy (UV, visible, infra-red and other). Compositions according to thepresent invention are preferably substantially non-toxic, non-flammablesafe compositions employing primarily biodegradable components for usein removing polymeric materials from substrates, for example, curedpaint from rigid and/or flexible surfaces. The compositions avoid theuse of methylene chloride, phenol, corrosives, methanol, toluol oracetone.

Compositions according to the present invention preferably have flashpoints above about 49° C. (about 120° F.) and a pH which is preferablyless than about 10-11, more preferably within a range of about 4 toabout 9, and most preferably about neutral pH (about 5.5-8.5).

In one aspect according to the present invention paint strippingcompositions are described which consist essentially of effectiveamounts of a light reactive polyene, generally a conjugated polyene,preferably a conjugated terpene compound or other natural productcontaining conjugated carbon-carbon double bonds in combination with aneffective amount of a solubilizing alcohol, more preferably aphenyl-substituted benzyl alcohol or a terpene alcohol. Benzyl alcoholis the most preferred alcohol for use in the instant invention.

The alcohol may be a monohydroxy alcohol generally selected from thegroup consisting of butanol, pentanol, hexanol, heptanol, octanol,nonanol, decanol, undecanol, dodecanol, benzyl alcohol, cyclopentanol,cyclohexanol, isomers of these alcohols and mixtures, thereof. Terpenealcohols and benzyl alcohol may also be preferably used in the presentinvention as an alcohol. Examples of terpene alcohols include forexample, dimethyl octanol, dihydromyrcenol, dihydroterpineol,dihydrolinalool, citronellol, dihydrocarveol, geraniol, arbanol,linalool, nerol, menthol, nopol, cis-2-pinanol, fernlol,tetrahydrolinallol, tetrahydromyrcenol, tetralol and mixtures thereof,among numerous others. Benzyl alcohol and phenyl substituted benzylalcohols and other "activated alcohols" including activated terpenealcohols, are especially preferred for use in the present invention,with benzyl alcohol being most preferred.

Phenyl-substituted benzyl alcohols also may be used in the presentinvention. Examples of phenyl-substituted benzyl alcohols for use in theinstant invention include those compounds according to the structure:##STR1## where R₁ -R₅ are H, C₁ -C₅ alkyl, NH₂, OH or OCH₃ ; with theproviso that when one of R₁, R₂, R₃, R₄ or R₅ is NH₂, OH or 0CH₃, theremainder of R₁, R₂, R₃, R₄ or R₅ are H or C₁ -C₃ alkyl.

In the present invention, the use of benzyl alcohol or analkyl-substituted benzyl alcohol (most preferably, C₁ -C₃ alkylsubstituted at the 2, 4 and/or 6 position of the phenyl ring) ispreferred, with benzyl alcohol being especially preferred. When analkyl-substituted benzyl alcohol is used (no other substitutents on thephenyl ring other than H), the alkyl groups are preferably substitutedon the 2, 4 and/or 6 positions of the benzene ring.

In addition to the above components, compositions according to thepresent invention preferably contain an effective amount of at least onethixotropic or rheological agent, more preferably an organoclayrheological additive and most preferably a hydrophilic organoclayrheological additive, for example, a hectorite clay such as Bentone "EW"or "LT" (available from NL Industries, Hightstown, N.J., U.S.A.). Amixture of a non-hydrophilic organoclay (for example, organic,non-hydrophilic Bentones) and a hydrophilic organoclay rheologicaladditive is preferred for use in the instant invention. The amount ofthixotropic agent included in compositions according to the presentinvention ranges from about 0.05% to about 60% by weight of thecompositions.

The present invention relates to the unexpected discovery that theinclusion of a conjugated polyene in combination with an alcohol ofdeterminate structure produces a composition which removes polymericcoatings from flexible and inflexible surfaces in the presence of alight or heat source (UV or visible light source, infrared or convectionheat source) at an unexpectedly rapid rate. Preferred compositions alsoexhibit substantially non-toxic and substantially biodegradable chemicalcharacteristics.

In addition to a light reactive polyene and solubilizing alcohol,compositions according to the present invention preferably include aterpene compound other than a conjugated terpene in an amount rangingfrom about 0% to 70% or more by weight as well as other components whichare optional, including one or more of the following: about 0.1% toabout 20% by weight of a surfactant, about 5% to about 30% by weight ofa solvent extender or bulking agent such as isopropanol or ethanol, andabout 0.5% to about 20% by weight of an odor masking component, forexample d'limonene (which also may be included as a terpene compound)and mixtures, thereof.

In a related aspect according to the present invention, a paintstripping composition consists essentially of about 10% to about 60% byweight of a terpene compound, preferably dipentene, in combination withabout 10% to about 95% by weight benzyl alcohol, preferably about 20% toabout 50% by weight, about 0% to about 50% by weight of a terpenealcohol and about 0.05% to about 60% by weight of a hydrophilicorganoclay thixotropic agent. This aspect of the instant invention isdirected to compositions which make use of the paint stripping efficacyof a terpene compound in combination with an effective amount of benzylalcohol. In order to significantly enhance the efficacy of these paintstripping compositions within the general teachings of the presentinvention, it is preferred to add at least one conjugated diene terpenesuch as alpha-terpinene, myrcene, allo-ocimene, terpinolene orisoterpinolene or a related terpene in an amount ranging from at leastabout 5% to about 90% by weight of the final composition and morepreferably about 10% to about 40% by weight.

Although not required for activity, a UV or visible light absorber oractivator, such as Sanduvor VSU™ from Sandoz Chemicals Corporation,Charlotte, N.C. and chlorophyll may be included in certain compositionsaccording to the present invention in amounts effective to enhance thestripping efficiency of the compositions, generally about 0.5% to about5% or more by weight of the composition. Various types of chlorophyllmay be used in the present invention including chlorophyll a, b, c andd. Chlorophyll for use in the present invention may be purchased from anumber of suppliers, including Chart Corporation, Inc.

Chlorophyll acts as a catalyst in photosynthesis, using energy fromsunlight, combined with water and carbon dioxide to liberate oxygen inthe production of simple sugars. In the present invention, while notbeing limited by way of theory, it is believed that chlorophyll (as wellas other sensitizers, especially including UV sensitizers) acts topromote the formation of photo oxides (peroxides or other reactivespecies). A range of chlorphyll products in oil or water soluble form,coppered or uncoppered may be useful in the present invention. Theoil-soluble coppered and uncoppered chlorophylis have vegetable oil,vegetable fatty acids or white soft paraffin as diluents. A number ofchlorophyll products may be used in compositions according to thepresent invention in amounts ranging from about 0.1% to about 5% ormore.

Numerous other components may also be included in the compositions ofthe present invention, for example, solvents such as N-methylpyrrolidoneand related pyrrolidones and pyrrolidines, propylene, ethylene orbutylene carbonate, dibasic esters (generally, refined dimethyl,diethyl, dipropyl, diisopropyl or mixed esters (methyl, ethyl, propyl,isopropyl) of adipic, glutaric, succinic acids and mixtures thereof)such as those commonly used in currently marketed biodegradable paintstrippers, gamma-butyrolactone and other cyclic esters and relatedcompounds, among others. In certain cases, the inclusion of the dibasicesters and/or propylene, ethylene or butylene carbonate representpreferred embodiments. These components may be added in amounts rangingfrom about 2% to about 70% by weight of the final composition, with apreferred weight range being about 5% to about 40% by weight, morepreferably about 10% to about 30% by weight.

The components which are added in the paint strippers according to thepresent invention are preferably substantially biodegradable andsubstantially non-toxic.

The compositions of the present invention can be used to strip or removeconventional lacquers, varnishes, enamels, epoxy esters, epoxy amidesand acrylics, among other polymeric coatings. The time required to strippaint finishes completely is competitive with, or in certain casesbetter than that, of conventional strippers containing chlorinatedsolvents. Compositions according to the present invention, because oftheir high flash points, are often capable of removing multiple layersof paint and other polymeric coatings.

In certain aspects of the present invention, the instant paint strippingcompositions are quite effective in removing lead based paints fromsurfaces. This is an unexpected result.

The compositions according to the present invention are particularlyuseful for stripping the coatings from commercial aircraft and militaryequipment which coatings are known to be very difficult to remove. It isparticularly unexpected that compositions which are substantiallybiodegradable and substantially non-toxic would remove such coatings inrelatively short periods of time, i.e., less than about 5 hours and inmany cases less than two hours.

In removing coatings from surfaces, the compositions of the presentinvention produce a wrinkling or blistering of the polymer coating.While not being limited by way of theory, this fundamental blistering isbelieved to be produced by solvent interaction with the coating. Whennormally insoluble high molecular weight polymers are placed in contactwith an active solvent, the polymer absorbs the solvent and expandsuntil an equilibrium condition occurs. In order to accommodate theincreased volume and still remain within the original surface perimeter,the polymer tends to fold or wrinkle so as to relieve internal stresses.The solvent mixtures solvate the active groups of the polymer, and in sodoing, reduce solid to solid adhesion. The forces which build up in thepolymer generally, as a result of a combination of swelling and weakenedadhesion, are sufficiently high to tear the film loose from the surface.Wrinkle formation occurs because solvent penetration into the polymerand deterioration of the polymer bonds proceed at approximately the samespeed. There is rapid parting of the film from the substrate and almostas rapid rupturing of the film itself.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to the discovery that the inclusion oflight reactive or conjugated polyenes, preferably natural productconjugated polyenes such as terpenes in combination with a solubilizingalcohol such as benzyl alcohol, produce a paint stripping compositionwhich, when exposed to an energy source, preferably a light source(visible, UV and/or infrared) and/or a heat source, exhibitssurprisingly favorable polymer stripping activity when compared to priorart paint stripping compositions.

Compositions according to the present invention are preferablysubstantially biodegradable and substantially nontoxic. The terms"substantially non-toxic" and "substantially biodegradable" are usedthroughout the specification to describe the preferred characteristicsof compositions according to the present invention. One of ordinaryskill in the art will readily recognize that these terms are relativeterms, i.e., they are used to describe compositions according to thepresent invention relative to conventional paint strippers containingmajor amounts of methylene chloride, methanol, phenol and similarsolvents which are substantially toxic and substantiallynonbiodegradable. It is understood that while most of the preferredcomponents which are used in the preferred non-toxic and biodegradablecompositions according to the present invention are themselvessubstantially non-toxic and biodegradable, it is not required that allcomponents be non-toxic and biodegradable. One of ordinary skill in theart will recognize that minor quantities of toxic and/ornon-biodegradable components may be added to the preferred compositionsaccording to the present invention without materially altering the basicand novel characteristics of these compositions.

The present invention embodies the unexpected discovery that lightreactive polyenes, generally conjugated dienes, trienes and relatedpolyenes (including 1,4-enone systems) are believed to react with anoxygen source (molecular oxygen or other oxygen source) in the presenceof an energy source (light and/or heat such as a UV or visible lightsource or an infrared or convection heat source) to yield reactivespecies believed to be organic peroxides (photooxides). While not beinglimited by way of theory, these photooxides are believed to be highlyactive species which are particularly effective in combination with thedisclosed alcohols, in particular, benzyl alcohol or relatedphenyl-substituted benzyl alcohol compounds for use as paint strippingcompositions. It is the combination of a light reactive or conjugatedpolyene in combination with the disclosed alcohols, in the presence ofeffective amounts of light or heat energy, which is believed to beprimarily responsible for the enhanced activity exhibited bycompositions according to the present invention.

Compositions according to the present invention generally containeffective amounts of a conjugated or light reactive polyene to produceenhanced paint stripping activity. In general, an effective amount of aconjugated polyene for use in the present invention comprises about 2%to about 90%, preferably about 5% to about 50% and more preferably about10% to about 45% by weight of the compositions according to the presentinvention. A conjugated polyene for use in the present invention isgenerally an organic compound (i.e., contains carbon atoms) having atleast two double bonds (generally, carbon-carbon, or in the case ofenones, carbon-carbon/carbon-oxygen) in conjugation. Preferably, theconjugated organic compound is a natural product such as a conjugatedterpene compound or a polyene such as betacarotene or lycopene and morepreferably is a terpene having at least two double bonds in conjugation.

As used herein, the terms "conjugated polyenes and/or conjugated dienes"include organic compounds, preferably hydrocarbons, both natural andsynthetic which have at least two double bonds (and in certain casesthree or more bonds) in conjugation and are solids or have sufficientlyhigh flash points as liquids (generally, above about 49° C. or 120° F.)to be useful in paint stripping compositions according to the presentinvention. Conjugated polyenes and/or conjugated dienes are useful inthe present invention because of their ability to be activated in thepresence of a light and/or heat source (UV, visible, IR, convectionoven, etc.).

The term "conjugation" is used throughout the specification to describeat least two double bonds (either carbon-carbon orcarbon-carbon/carbon-oxygen) between alternating carbon atoms within acarbon chain. Thus, conjugated double bonds would be found between thefirst and second carbon atoms in a chain and at least the third andfourth (in certain cases also the fifth and sixth, seventh and eight,etc.) carbon atoms in the chain. In the case of conjugated systems whichare or contain 1,4-enone systems, a carbon-carbon double bond is foundbetween the carbon atoms alpha and beta to the "keto" or carbon-oxygendouble bond. Thus, the term "double bonds in conjugation" or "conjugateddouble bonds" includes dienes, triene, tetraenes, etc. and enones,dienones and trienones, etc. Conjugated terpene compounds are terpenecompounds which contain at least two double bonds (carbon-carbon orcarbon-carbon/carbon-oxygen) in conjugation as generally describedherein.

The terms "light reactive polyene" and "conjugated polyene" are usedsynonymously throughout the specification to describe conjugated organiccompounds, preferably conjugated hydrocarbons, more preferably naturalproduct conjugated hydrocarbons including conjugated terpenes, which arebelieved to form photooxides or other reactive species upon exposure toa light and/or heat source (preferably, UV, sunlight, other visiblelight, infrared or convection oven) alone or in the presence of aphotoactivating compound such as chlorophyll or a UV sensitizer.

While any number of synthetic conjugated polyenes may be used in thepresent invention, it is preferred that "natural product polyenes" beused, including "conjugated terpene compounds" as well as other naturalpolyenes such as beta-carotene and lycopene (each having 11 conjugateddouble bonds). The conjugated diene systems which are useful in thepresent invention include carbon-carbon double bonds in conjugation aswell as carbon-carbon/carbon-oxygen double bonds in combination (such as1,4-enone, dienone and trienone systems). Terpene polyene compounds foruse in the present invention include, for example, alpha-terpinene,myrcene, hymentherene, cosmene, tagetol, phellandrene, citral, ocimene,ocimenone, myrcenol, terpinolene, allo-ocimene, ocimenone, tagetone,tagetol, pseudoionone, pseudomethylionone and pseudoisomethylionone,among others. Certain mixtures of terpenes, for example, those whichcontain substantial quantities (about 5% or more by weight) ofalpha-terpinene and/or other conjugated terpene compounds generally setforth hereinabove, such as terpene mixture Dipentene "D™", "M™" or "C™",available from Pine Derivatives Marketing, Inc. (PDM), Wilmington, Del.,may also be used in the present invention. The conjugated terpenecompounds, and especially, alphaterpinene, tagetone, terpinolene,isoterpinolene, allo-ocimene, myrcene and ocimenone are preferred foruse in the present invention, because of the relative absence oftoxicity, substantial biodegradability and relative activity of thesecompounds compared to conventional components such as methylenechloride, phenol and methanol.

While the use of alpha-terpinene and terpene compounds containingsubstantial quantities of alpha-terpinene and related conjugated terpenecompounds are preferred, a number of conjugated polyenes may be used aspreferred substitutes in the present invention. The conjugated terpenesmyrcene, allo-ocimene, terpinolene, isoterpinolene and alpha-terpineneare more preferred for use in the present invention, withalpha-terpinene being most preferred.

The visible portion of the electromagnetic spectrum as well as UVA (320to 400 nm) and UVB (about 240 to 320 nm) contribute to the photoactivityof the compositions, depending upon the light reactive componentsutilized. UVB has a significant influence on the reactivity ofcompositions which contain conjugated terpenes, in particular,alpha-terpinene and myrcene. UV absorption is believed to be the primaryenergy source for the formation of photooxides and other reactivespecies; however, heat energy in the form of infrared or convectionenergy may also be used alone or in combination with UV or visible lightenergy. The amount of light or heat energy used is that amount effectiveto substantially enhance the stripping efficiency of the presentcompositions compared to the same compositions which are not exposed tolight and/or heat energy (at least about room temperature). Formation ofphotooxides in the presence of visible light may be facilitated by theaddition of a photoactivating compound such as chlorophyll. Theinclusion of heat from a heat source such as an infrared source orconvection oven may also enhance reactivity, with temperatures aboveabout room temperature being preferred. Temperatures of about 23° C. toabout 63° C. (72° F. to about 145° F.), more preferably about 43° C. toabout 63° C. (about 110°-145° F.) from an infrared or convection sourcealone, or in combination with UVB light is a preferred source of energyfor enhancing activity and promoting the stripping efficiency of thecompositions according to the present invention.

In addition to a light reactive or conjugated polyene, compositionsaccording to the present invention may include an alcohol selected fromthe group consisting of butanol, pentanol, hexanol, heptanol, octanol,nonanol and decanol, among others, including isomers of these alcoholsas well as mixtures, thereof. Preferred alcohols for use in the presentinvention include those alcohols which contain flash points above about49° C. (120° F.).

More preferred for use in the present invention are "activatedalcohols", including benzyl alcohol or any one or more substitutedbenzyl alcohols (substituted on the benzylic carbon position or any oneor more phenyl carbons), among others, including activated terpenealcohols, as described hereinbelow. The term "activated alcohol" is usedto describe an alcohol which contains a carbon-carbon double bond or aconjugated system (such as a phenyl group) at a position alpha to thehydroxylated carbon of the alcohol. More preferably, benzyl alcohol (ora related phenyl-substituted benzyl alcohol compound as disclosedherein) is used as the alcohol in the present invention. Benzyl alcoholis the most preferred alcohol for use in the present invention. Whilenot being limited by way of theory, it is believed that the activatedalcohol and especially benzyl alcohol may actually participate in thestripping activity either by enhancing the stripping efficiency of thecompositions or by solubilizing the coating to be removed from asurface.

Phenyl-substituted benzyl alcohols also may be used in the presentinvention. Examples of phenyl-substituted benzyl alcohols for use in theinstant invention include those compounds according to the structure:##STR2## where R₁ -R₅ are H, C₁ -C₅ alkyl, NH₂, OH or OCH₃ ;

with the proviso that when one of R₁, R₂, R₃, R₄ or R₅ is NH₂, OH orOCH₃, the remainder of R₁, R₂, R₃, R₄ or R₅ are H or C₁ -C₃ alkyl.

In the present invention, the use of benzyl alcohol or analkyl-substituted benzyl alcohol (most preferably, C₁ -C₃ alkylsubstituted at the 2, 4 and/or 6 position of the phenyl ring) ispreferred, with benzyl alcohol being especially preferred. When analkyl-substituted benzyl alcohol is used (no other substitutents on thephenyl ring other than H), the alkyl groups are preferably substitutedon the 2, 4 and/or 6 positions of the benzene ring.

The alcohol is used in compositions according to the present inventionin amounts effective to enhance the paint stripping activity of thereactive polyene. The amount of alcohol in the present compositionsranges from about 5% to about 95% by weight of the composition, morepreferably about 10% to about 60% by weight and most preferably about20% to about 50% by weight. The amount of conjugated polyene used incompositions according to the present invention generally ranges aboveabout 2%, usually within the range of about 5% to about 90% by weight.The amount of conjugated polyene will vary within this weight range as afunction of its photoreactivity and its ability to interact with thesolubilizing alcohol included in the compositions to remove polymersfrom substrates. The conjugated polyene is preferably included inamounts ranging from about 10% to about 40% by weight of thecomposition.

The preferred alcohol for use in the instant invention is benzyl alcoholor a phenyl substituted benzyl alcohol at a weight ratio of about 10% toabout 95% by weight, and a preferred weight ratio of about 20% to about90% by weight, more preferably about 30% to about 50% by weight. Thealcohol is most preferably benzyl alcohol. The preferred conjugatedpolyene is a conjugated terpene. The conjugated terpene is preferablyselected from alpha-terpinene, myrcene, terpinolene, isoterpinolene,allo-ocimene and mixtures, thereof. The conjugated terpene is mostpreferably alpha-terpinene which is included at a preferred weight ratioof about 10% to about 40%. In compositions which utilize both benzylalcohol and a conjugated terpene, the weight ratio of benzyl alcohol toterpene ranges from about 1:1 to about 10:1, with a preferred weightratio when alpha-terpinene is the conjugated terpene of about 1:1 toabout 3:1 (benzyl alcohol to alpha-terpinene).

In addition to a light reactive or conjugated polyene, the compositionsof the present invention optionally may comprise from about 2% to about70% by weight of a terpene compound other than a conjugated terpenecompound. As used herein, the term terpene compound refers to a class ofacyclic and cyclic unsaturated compounds derived from natural essentialoils and resins having at least 10 carbon atoms. Terpenes that find usein the present invention include alcohols and aldehydes as well asunsaturated hydrocarbons. Any number of terpene compounds, includingcombinations of these terpenes may be used in the present invention asthe base or primary solvent as polymer absorbents. Preferred terpenecompounds are those compounds which have a K_(B) value of at least about60 and a flash point above about 49° C. (about 120° F.).

In the case of compositions which include a thixotropic agent, anorganoclay rheological additive is most preferably added. Thixotropicagents are included in the instant compositions in amounts ranging fromabout 0.05% to about 60% by weight. Preferably an organoclay rheologicaladditive (a modified smectite or hectorite clay) is utilized. Morepreferably a hydrophilic organoclay rheological additive is included,for example, a modified hectorite clay such as Bentone "EW" or "LT" isincluded in amounts ranging from about 5% up to about 50% by weight,more preferably about 10% to about 45% by weight. Most preferably amixture of a non-hydrophilic organoclay rheological additive (forexample, an organic, non-hydrophilic Bentone) and a hydrophilic organicrheological additive is included. This combination has been shown toprovide acceptable rheology which is consistent with the use on verticalsurfaces of paint strippers according to the present invention. Incertain instances where a hydrophilic organoclay rheological additive isincluded, a polar activating solvent such as ethanol, isopropanol,propylene carbonate, N-methylpyrrolidone, benzyl alcohol or a relatedsolvent or a mixture of water and activating solvent may be included inamounts generally ranging from about 0.5% to about 20% or more,preferably about 3% to about 18% by weight of the compositions. Watermay also be included in the instant compositions, but in many instances,the inclusion of water is less preferred.

K_(B) is a measure of the solvency of a hydrocarbon. In general, thehigher the K_(B) value, the greater the general solvent power of thehydrocarbon under test conditions described by ASTM D1133. To determineK_(B) value, a hydrocarbon sample is added to a standard solution ofkauri gum in butyl alcohol until sufficient kauri gum precipitates toblur vision of 10 point type viewed through the flask. When used invarnish, lacquer and enamel formulations, a hydrocarbon diluent with ahigh K_(B) value dissolves relatively large quantities of solids.

Terpene compounds (other than conjugated. terpene compounds or terpenealcohols) which may optionally be added to the light reactive orconjugated polyenes and solubilizing alcohol included in the presentinvention are represented by unsaturated hydrocarbons and aldehydeshaving at least 10 carbon atoms and include alpha-pinene, beta-pinene,delta-3-carene, citronellal, d-limonene, gamma-terpinene, and dipentene,among numerous others, with cyclic terpenes being preferred.

The present invention may include terpene alcohols. Terpene alcoholswhich find use in the present invention include for example, dimethyloctanol, 3-octanol, dihydromyrcenol, dihydroterpineol, dihydrolinalool,citronellol, allo-camenol, dihydrocarveol, geraniol, arbanol, linalool,nerol, menthol, nopol, cis-2-pinanol, isoborneol, fernlol, farnesol,fenchol, nerolidol, piperitol, borneol, cineol, isobulegol, allcimenol,tetrahydrolinallol, tetrahydromyrcenol, tetralol, tagetol, and mixturesthereof. Terpene alcohols are terpene compounds which contain an alcoholchemical functionality. The terpene alcohols may be used alone or incombination with other terpene compounds. Preferred terpene alcohols foruse in the present invention include geraniol, tagetol, carveol,linalool, myrcenol and nerol. A preferred combination of terpenecompounds is dipentene in combination with a terpene alcohol as setforth above. Terpene alcohols are generally included in compositionsaccording to the present invention in amounts ranging from about 0% toabout 50% by weight or more up to about 90% by weight and are preferablyincluded in amounts ranging from about 5% to about 50% by weight, morepreferably about 10% to about 40% by weight. Activated alcohols such asbenzyl alcohol and the activated terpene alcohols such as geraniol,linalool, nerol, myrcenol, tagetol and carveol may generally be used inamounts ranging from about 5% to about 90% by weight.

Compositions of the present invention optionally include about 0% toabout 60% by weight of a terpene compound other than a conjugatedterpene or terpene alcohol. Preferred compositions of the presentinvention may comprise between about 5% to about 55% by weight, and mostpreferably, between about 10% and about 50% by weight of a terpenecompound other than a conjugated terpene compound or terpene alcohol.

Compositions according to the present invention also include at leastabout 0.05% (generally, up to about 60%) by weight of a thixotropicagent, preferably about 5% to about 50% and more preferably about 10% toabout 45% by weight. The preferred thixotropic agent is an organoclaythixotropic agent, such as Bentone 27, 38, EW and LT. Hydrophilicorganoclay thixotropic agents such as Bentone EW and LT are morepreferred. Mixtures of hydrophilic and non-hydrophilic organoclaythixotropic agents in amounts ranging from about 10% to about 45% byweight of the compositions are especially preferred. The inclusion oforganoclay rheological additives are especially useful for enhancing therheology of the formulations to produce high viscosity compositions inorder to use the stripping compositions on vertical surfaces.

In the method aspects of the present invention, compositions of thepresent invention are used to strip and/or remove polymeric coatings ona number of surfaces, preferably in the presence of a light and/or heatsource which imparts effective amounts of light and/or heat energy tothe polymeric coating to be removed.

Depending upon the formulation of the composition to be used, furtheraspects of the present invention involve making the compositions of thepresent invention using a step-wise procedure in which thixotropicagents are mixed separately from the active ingredients. Certainthixotropic compositions, for example methylcellulose, such as Methocel311, available from Dow Chemical Corp. Midland, Mich., hydroxypropylcellulose, Klucell™, available from Hercules, Inc., Wilmington, Del.,ethyl cellulose, such as Bermocol PR™, available from Seaboard Sales,New Jersey) and clays modified with quaternary compounds (high, mediumand low polar), such as Bentone 27, Bentone EW and Bentone LT, productsof NL Industries, New Jersey, U.S.A. may be used in the instantinvention, among others.

The compositions according to the present invention may advantageouslyutilize gel formation to produce a composition exhibiting enhancedstripping activity and acceptable thixotropy for stripping or removingpolymeric coatings on vertical surfaces. Microgel formation usingcellulose ether may be advantageously employed using this method.

Preferred organoclay rheological additives include organoclayrheological additives made from smectite and/or hectorite clays modifiedwith quaternary compounds (high, medium and low polar), such as thestearalkonium hectorites (hectorite clays), for example, Bentone 27,Bentone 38 and the hydrophilic clays such as Bentone EW™ and BentoneLT™, products of NL Industries, New Jersey, U.S.A., with the hydrophilicBentones™, especially Bentone EW™ and LT™ being particularly preferred.

The organoclay additives are preferably utilized as thixotropic agentsin the compositions of the present invention. The organoclays which canbe utilized in the present invention generally depend on wetting, shearand polar activation for rheological development. One class of theorganoclays, the high performance hydrophilic organoclays, includingBentone EW™ and Bentone LT™, depend only upon shear, hydration andwetting for activity. They are especially useful in the compositionsaccording to the present invention. These hydrophilic organoclays mayoffer the formulator opportunities to incorporate large quantities ofthixotropic agent in the compositions without appreciably impacting theactivity of the compositions. The result is a composition in the form ofa paste having very high viscosity which may be advantageously appliedto a variety of vertical surfaces for removing polymers.

In certain embodiments where certain terpenes such as dipentene areused, a malodor sometimes occurs. In such cases, a natural odor maskingterpene compound, for example, d'limonene, among other odor maskingagents, may be added in an amount ranging from about 0.25% to about 20%by weight in order to make the compositions more pleasant in odor.D'limonene may also be added for its beneficial effects as a terpenecompound for use in the present invention.

In many instances, it will be unnecessary to include a surfactant in thepaint stripping composition. However, in certain embodiments accordingto the present invention a surfactant may be advantageously included inan effective amount, i.e., an amount equal to about 0.1% to about 20% byweight and preferably about 0.1% to about 15% by weight of the paintstripping compositions of the present invention. The surfactant isprimarily added to compatibilize the componentry of the paint strippingcompositions and to instill better water dispersibility for purposes ofremoving the compositions from walls, panels and other surfaces withwater.

In compositions containing organoclay rheological additives such as theBentones™, when surfactants are included, they generally comprise about0.1% to about 20% by weight of the composition.

Numerous surfactants capable of emulsifying the components of thepresent invention may be employed, including but not limited to linearor branched chain alcoholic ethoxylates and ethoxysulfates, alcoholethoxylates, polysorbate esters, ethoxylated alkylphenols, for example,polyethoxynonylphenols, phenoxypolyalkoxyalcohols, for example,nonylphenoxypoly(ethyleneoxy)ethanol and nonylphenoxypolyethoxyethanol,alkyl and alkyl ether sulfates and sulfonates, for example,dodecylbenzenesulfonic acid, alkyl and dialkyl succinate compounds,phosphate esters, for example phosphate esters of long-chain alcoholethoxylates and combinations of these surfactants. Other surfactants foruse in compositions of the present invention include the phosphate estersurfactants, such as PD-600™, an alkaline stable mixture of mono anddi-substituted phosphate esters of decylalcoholethoxylate, availablefrom Chemax, Inc. (Greenville, S.C.) and the Tryfac™ phosphate esters, aseries of phosphate ester surfactants as the free acids or varioussalts, available from Emery Chemicals, Mauldin, S.C. Other surfactantsinclude polyoxyethylenenonylphenol (NP-6™ and NP-9™, available fromChemax, Inc., Greenville, S.C.) as well as the nonionicalkylphenoxypolyoxyethylene alcohols, the Makon™ series, available fromStepan Company, Northfield, Ill. Alkylamine dodecylbenzenesulfonateNinate 411™, available from Stepan Company, the linear alkylbenzenesulfonic acid surfactant Bio-soft s-100™, available from Stepan, sodium1-octane sulfonate, Bioterge pas-8s™, available from Stepan and Neodol1-5™, a nonionic surfactant having an average of 5.0 ethylene oxideunits per molecule of alcohol, available from Chemax, Inc., are alsouseful in the present invention. A preferred surfactant for use in paintstrippers having an alkaline or basic pH includes CSX-727, an alkalinestable surfactant also available from Chemax, Inc. These surfactants maybe used alone or in combination to enhance the activity of the terpinoidand and to produce paint strippers having excellent paint strippingactivity.

The pH of the paint stripper compositions of the present invention mayvary over a relatively wide range generally under a pH of about 10-11.Preferred compositions generally have a pH ranging from about 4 to about9, and most preferably have a neutral pH (about 5.5 to about 8.5).Certain paint strippers of the present invention which are to be used asindustrial or military paint strippers may be quite alkaline, i.e., havea pH approaching 12.0 or more or have a pH which is quite acidic, i.e,about 2.5 or lower. In instances where a higher pH is desired, a base,preferably a biodegradable amine containing base, is included in thecompositions. Exemplary amines included for the purpose of raising thepH of the composition include, for example, aminomethylpropanol, mono-,di- and trimethylamine, mono-, di- and triethylamine, mono-, di- andtri-propylamine, triisopropylamine and related amine containing bases.Triethanolamine and ethanolamine, among other amine containing bases,may also be used to increase the pH of the compositions when necessary.Aminomethylpropanol, triethanolamine, ethanolamine and triethylamine arethe preferred amine bases for inclusion in the present compositions,with aminomethylpropanol being especially preferred.

In cases where it is desired to have a low pH, for example a pH of about3.5 or less, an acid may be added to the compositions according to thepresent invention. Preferred acids include the low pKa organic acids(pka's generally less than about 3.0) such as maleic acid, and otheracids such as sulfamic acid and phosphoric acid, among others. Inaddition, in order to lower the pH of the composition for certainapplications, an acidic phopshate ester surfactant such as PD-600™,among others, may also be added to the compositions.

The compositions according to the present invention, for routine paintand polymer removal, are preferably neutral in pH (about 5.5 to 8.5). Itis an unexpected results that paint stripper compositions of the presentinvention show substantial paint stripping activity in the industrialsetting within a neutral pH range. Thus, although an acidic or basicaccelerator may be added to compositions of the present invention toincrease stripping efficiency and shorten stripping time, such an acidicor basic accelerator is often not necessary. In compositions to be usedin the home by the consuming public, it is preferred to exclude anacidic or basic accelerators to increase the safety. In certainpreferred organoclay containing compositions, enhanced paint strippingactivity is associated with a neutral pH, i.e., about 5.5 to about 8.5.

Anionic, nonionic and cationic surfactants may be employed in certainembodiments of the present invention which include a surfactant. It maybe preferable in certain embodiments of the present invention to includea mixture of surfactants to enhance the solubility of certain activecomponents in oil or water. A surfactant mixture may serve to promotethe stripping of the polymeric coating by the active components andenhance the removal of the stripper and stripped coating by a washingstep.

Although not required for activity, a UV or visible light absorber oractivator, such as Sanduvor VSU™ from Sandoz Chemicals Corporation,Charlotte, N.C., among a number of others as well as chlorophyll may beincluded in certain preferred compositions according to the presentinvention in amounts effective to enhance the stripping efficiency ofthe compositions when exposed to a UV or visible light source, and ingeneral about 0.1% to about 5% or more by weight. Chlorophyll may beadded to compositions which are used as paint strippers for external oroutdoor use, such as on home exteriors, bridges and in other outdoorapplications where sunlight is expected to be the principal source oflight energy.

In preferred embodiments, various types of chlorophyll may be used inthe present invention including chlorophyll a, b, c and d, availablefrom a number of suppliers, including Chart Corporation, Inc.

In addition to the above-described components, compositions according tothe present invention may optionally include solvents such asN-methylpyrrolidone and related pyrrolidones and pyrrolidines,propylene, ethylene and butylene carbonate, the dibasic esters (aspreviously described) of adipic, glutaric, succinic and mixturesthereof, gamma-butyrolactone as well as other cyclic esters and relatedsolvents, among others. These optional solvents may be included inamounts ranging from about 0% to about 50% or more by weight or more ofthe instant compositions. One of ordinary skill will readily know tovary the amount and type of solvent to the present compositions toenhance various characteristics and/or attributes.

Other optional additives which may be included in paint strippingcompositions according to the present invention include a solventextender such as ethanol or isopropanol in an amount ranging from about5% to about 30% by weight, water in amounts ranging from about 0% toabout 25%, about 0.25% to about 20% by weight of an odor-maskingcompound, preferably d'limonene, and mixtures thereof.

The compositions of the present invention are generally applied to thesurface to be stripped in the usual manner, i.e., the compositions arefirst applied by brush, spatula or other applicator and then are appliedto the surface to be stripped. Alternatively, the compositions may besprayed onto a surface in a continuous flow method which recirculatesthe composition or alternatively sprayed onto the surface using anairless spraying system, such system taking advantage of the thixotropiccharacteristics of the compositions under shearing force and on verticalpanels.

Generally, the compositions are in contact with the surface for a periodof time sufficient to produce a blistering of the polymeric coating,after which time, the blistered coating is removed by contacting thecoating with an abrasive pad. Alternatively, the coating is removed bysimply lifting the blistered coating off of the surface or by sprayingthe blistered coating with water. In many instances, the compositionsaccording to the present invention will strip seven or more coats ofpaint in as little as four hours or less.

Because exposure of the compositions to light (UV or visible) and/orheat (IR, convection) energy will enhance the stripping activity of thepresent invention, it is preferred that the stripping be performed inthe presence of at least some light and heat energy. Bright visiblelight (in particular, bright sunlight) and UV light will be generallyeffective alone or optionally, in the presence of a photoactivator orsensitizer. The use of heat energy (in the form of infrared orconvection heat) alone is also a favorable option and may be employedefficiently in enhancing the activity of compositions according to thepresent invention in removing paint and polymers from surfaces.

The method of stripping paint or polymers using the present inventionemploys the introduction of an effective amount of a paint strippercomposition according to the present invention onto the surface to bestripped (generally, a thin layer which completely covers the surface tobe stripped; with thicker coats of polymer to be removed, a thickerlayer of stripper may need to be deposited) and introducing light and/orheat energy onto the surface which contains the stripping compositionand the polymer to be removed. Although the amount of light and/or heatenergy may vary, in the case of the use of light energy, it has beenfound that stripping activity increases as the amount of light energyapplied to the surface to be stripped is increased. Thus, the use ofdirect sunlight, or a UV lamp (preferably emitting UVB or alternatively,a combination of UVA and UVB light energy) which is held close to thesurface of the polymer to be stripped or alternatively, is an intensesource of light, may be advantageously employed in the presentinvention. The amount of light and/or heat energy applied to a surfaceis an effective amount for enhancing the stripping efficiency ofcompositions according to the present invention. One of ordinary skillin the art will readily recognize that the type and amount of lightenergy to be delivered to the surface containing the polymer to beremoved and the stripping composition may vary according to the activityof the stripping composition, the amount of composition deposited ontothe polymer surface to be removed and the relative degree of difficultyremoving the polymer from the surface.

Paint stripping compositions according to the present invention may alsobe activated in the presence of heat energy. Heat energy may beintroduced by any means, but is preferably introduced onto the surfaceof the coating to be stripped using a simple convection source. Aninfrared heat source may also be used. Alternatively, in the case ofmetallic or composite substrates which are heat conductors, it may bepossible to heat the underlying surface directly (electronically orusing heat coils, etc.). In general, when heat is used as an energysource, the paint stripping composition should attain a temperature ofat least about 23° C. (about 72° F.), preferably at least about 32° C.(about 90° F.), more preferably at least about 43° C. (about 110° F.).Preferably, the temperature should be no higher than about 63° C. (about145° F.), because at temperatures above about 63° C., solvent may beginto evaporate from the surface to be stripped, thus actually reducing theactivity of the composition. As one increases the temperature of thecomposition and substrate to be stripped, the stripping activity andefficiency generally increase up to a point.

A combination of heat and light energy, as generally describedhereinabove is a preferred method for stripping paint. One of ordinaryskill will know to vary the temperature and the type and amount of lightenergy to which the polymer to be stripped and the paint strippingcompositions according to the present invention are exposed in order toenhance and facilitate the removal of polymeric coatings using the paintstripping compositions according to the present invention.

The following characterics are identifiable in one or more embodimentsaccording to the present invention:

(1) Increased stripping efficiency, i.e., reduced stripping time basedupon enhanced reactivity in the presence of light (visible or UV) and/orheat (about 23°-60° C.).

(2) Raised flash point of the formulations to provide a stripper whichwill not evaporate appreciably within a stripping period.

(3) Minimized objectionable odors.

(4) Neutral pH for widest possible range of utilization and safety.

(5) Highest possible TLV (threshold limit value) and exposure, lowesttoxicity, and maximum environmental acceptability.

(6) A water dispersible stripper composition which can be used inindustrial settings where removal is performed by spraying a strippedsurface with water.

The following examples are provided to illustrate the present inventionand should not be misunderstood or misinterpreted to limit the scope ofthe present invention in any way.

EXAMPLES 1-51

General Procedure for Formulating Examples 1-51

Each component to comprise the paint stripping composition of thepresent invention is weighed out. The components are mixed in an orderwhich minimizes exposure of the alcohol to the conjugated terpene. Incertain instances, the conjugated polyene such as a conjugated terpeneand thixotropic agent are first blended to produce a part A. Chlorophyllas well as other components may also be added to this part A orseparately to part B, but generally, the alcohol is mixed separatelyfrom the conjugated terpene with other components to produce a part Bwhich is eventually added to part A. This mixture is then agitated orsimply mixed by hand until the composition is homogeneous. In anindustrial setting it is anticipated that a high speed industrial mixerwill be used to prepare the compositions in order to activate theorganoclay thixotropic agent.

General Testing Procedures

Standardized test panels coated with the substrate to be stripped areprepared. Enamels, alkyds, epoxies, latex, acrylics and, conventionallacquers were tested. All testing was performed on metal plates with atleast three coats of paint, often with as many as seven coatings ofpaint, each coat having a different color so as to permit observationand time measurement of coating penetration. Stripping efficiency isdefined as the ratio of the time required to observe blistering dividedby 20 (minutes).

The testing of strippers occurred by placing aliquots of paint stripperonto test panels. Utilizing standard test plates, a dropletapproximately 1/2 inch in diameter of a stripping composition is placedonto the test plate in the presence of a light source, and the timeuntil the coating blisters is then measured. The most challengingsubstrates were chosen to be stripped, to establish the performancecriteria expected of competitive paint strippers.

The first experiments (Examples 1-8) and tests were performed todetermine whether preparations of photo-active compositions could beutilitarian in paint remover applications. Compositions were prepared,and aliquots applied to aluminum alloy panels coated with anepoxy/polyurethane paint system with a polysulfide sealant. The panelsare samples of the paint system applied to naval aircraft and weresupplied by the Naval Air Development Center. These coatings areextremely difficult to remove; conventional paint strippers havedifficulty blistering and removing these tough military coatings.

In examples 9-51, test panels were prepared having seven differentcoatings of paint in addition to a primer coating. In addition to primercoating, the test panels had coatings of high gloss house paint, alkydenamel, acrylic latex house paint, heavy duty polyurethane enamel, otheralkyd enamel, rust inhibitive paint and latex semi-gloss paint. Thepanels were prepared to provide a representative cross-section of amajority of the different (chemical) types of coatings which arepresently being used.

EXAMPLES 1-8

Examples 1-8 were performed to determine the utility of compositionscontaining a conjugated terpene in combination with benzyl alcohol andchlorophyll. Examples 2-6 monitored the use of thixotropic agent, inparticular, an organoclay thixotropic agent. All compositions proved tobe adequate in paint stripping activity. Based upon these examples, theinclusion of thixotropic agent was clearly beneficial in producingadequately performing paint stripper compositions.

Examples 6 and 7 were performed to determine the beneficial effect onthe compositions by including Bentone 38 in the compositions. InExamples 5, 6 and 8, AMP-95, Witflow 934 and/or Hydral were added todetermine the effect that alkalinity had on the relative activity of thecompositions. Results indicated that the thixotropic agent plays anessential role in the useability of the compositions and alkalinity isnot essential for obtaining exceptional paint stripping activity.

Test speciments, with aliquots from Examples 1-9 applied, and blankspecimens were subjected to UV light (at a wavelength ranging from 200to 400 nm) at 32° C. (about 90° F.) in a controlled environment. Thepanels were examined at 15 minute intervals. After 45 minutes, both setsof specimens were carefully examined. Speciments with aliquots appliedto coatings generally had blistered within the 45 minute period with thecoating being lifted cleanly from the alcad specimens.

EXAMPLE 1

    ______________________________________    Components      percent (wt.)    ______________________________________    Alpha-Terpinene 27.0    Chlorophyll DD  1.0    Benzyl Alcohol  72.0    ______________________________________

This composition exhibited acceptable stripping efficiency and activitybut tended to run on vertical or sloping surfaces.

EXAMPLE 2

    ______________________________________           Alpha-Terpinene                      30.0           Chlorophyll DD                      1.0           Benzyl Alcohol                      65.0           Cyasorb UV-9                      1.0           Bentone 27 3.0    ______________________________________

Bentone 27 was added in this example to facilitate the binding of thecomposition and prevent migration of the composition when applied totest specimens (panels). In addition, in Examples 2-6, a number ofdifferent UV sensitizers (Cyasorb) were added to the chlorophyll todetermine the activity of the compositions.

EXAMPLE 3

    ______________________________________           Alpha-Terpinene                      30.0           Chlorophyll DD                      1.0           Benzyl Alcohol                      65.0           Cyasorb UV-531                      1.0           Bentone 27 3.0    ______________________________________

EXAMPLE 4

    ______________________________________           Alpha-Terpinene                      30.0           Chlorophyll DD                      1.0           Benzyl Alcohol                      65.0           Cyasorb UV-5411                      1.0           Bentone 27 3.0    ______________________________________

EXAMPLE 5

    ______________________________________           Alpha-Terpinene                      30.0           Chlorophyll DD                      1.0           Benzyl Alcohol                      53.0           Cyasorb UV-24                      1.0           Bentone 27 3.0           AMP-95     10.0           Witflow 934                      2.0    ______________________________________

In this example 5, AMP-95 (aminomethylpropanol) and Witflow 934 (analkaline surfactant) were added to the composition to determine theeffect that alkalinity has on the activity of the compositions.

EXAMPLE 6

    ______________________________________           Alpha-Terpinene                      30.0           Chlorophyll DD                      1.0           Benzyl Alcohol                      40.0           Cyasorb UV-24                      1.0           Bentone 38 3.0           AMP-95     23.0           Witflow 934                      2.0    ______________________________________

Bentone 38 was substituted for Bentone 27 because of its favorablethixotropic properties. Stripping efficiency about the same as othercompositions but workability and useability was enhanced somewhat by tothe choice of thixotropic agent. Based upon the results obtained forExamples 2-6, it was concluded that alkalinity is not critical tostripping efficiency.

EXAMPLE 7

    ______________________________________           Alpha-Terpinene                      30.0           Chlorophyll MM                      1.0           Benzyl Alcohol                      66.0           Bentone 38 3.0    ______________________________________

EXAMPLE 9

    ______________________________________           Alpha-Terpinene                      30.0           Chlorophyll MM                      1.0           Bentone 38 3.0           Benzyl Alcohol                      40.0           Bentone (EW)                      6.0           AMP-95     6.0           Witflow 934                      2.0           Hydral     12.0    ______________________________________

AMP-95, Witflow 934 and Hydral were used during experimentation to testwhether alkalinity was a required property. These components areaminomethylpropanol, an alkaline surfactant and hydrated aluminumhydroxide (hydrated with 3 water molecules). Tests performed on specimenpanels evidenced that alkalinity was not required for activity. In manyexperiments thereafter, alkaline components were eliminated fromsubsequent experiments. The inclusion of Bentone EW (a hydrophilicorganoclay thixotropic agent) did improve the workability and efficiencyof stripping on vertical surfaces.

EXAMPLES 9-14

Standardized 9"×12" test panels were prepared for testing the followingcompositions (Examples 9-51). Each panel of regular plywood sheet hadseven separate coatings (high gloss house paint, alkyd enamel, acryliclatex house paint, heavy duty polyurethane enamel, other alkyd enamel,rust inhibitive paint and latex semi-gloss paint), applied in additionto a primer coating. The panels were cured after each coat was appliedin an oven at 49° C. (about 120° F.) for at least 24 hours.

Examples 9-14 were performed to determine the effect that a change inweight percent of conjugated terpene and benzyl alcohol would have onthe efficiency of the formulation. The amount of benzyl alcohol whichwas considered optimum was determined to be about 40% by weight. Inaddition, the effect of the inclusion of dipentene varying in KB wasassessed. The conclusion was that the KB value of dipentene playedlittle role in enhancing the stripping efficiency of the compositions,but the inclusion of dipentene was considered beneficial, although notcritical.

EXAMPLE 9

    ______________________________________    Alpha-Terpinene   30.0    Chlorophyll MM    .8    Bentone 38        3.0    Benzyl Alcohol    40.0    Dipentene (KB-100)                      20.2    Bentone (EW)      6.0    ______________________________________

EXAMPLE 10

    ______________________________________    Alpha-Terpinene   30.0    Chlorophyll MM    1.5    Bentone 38        3.0    Benzyl Alcohol    40.0    Dipentene (KB-100)                      19.5    Bentone (EW)      6.0    ______________________________________

EXAMPLE 11

    ______________________________________    Alpha-Terpinene   10.0    Chlorophyll MM    1.0    Bentone 38        3.0    Benzyl Alcohol    50.0    Dipentene (KB-100)                      30.0    Bentone (EW)      6.0    ______________________________________

EXAMPLE 12

    ______________________________________    Alpha-Terpinene   30.0    Chlorophyll MM    1.0    Bentone 38        3.0    Benzyl Alcohol    40.0    Dipentene (KB-100)                      20.0    Bentone (EW)      6.0    ______________________________________

EXAMPLE 13

    ______________________________________    Alpha-Terpinene   50.0    Chlorophyll MM    1.0    Bentone 38        3.0    Benzyl Alcohol    30.0    Dipentene (KB-100)                      10.0    Bentone(EW)       6.0    ______________________________________

EXAMPLE 14

    ______________________________________    Alpha-Terpinene   50.0    Chlorophyll MM    1.0    Bentone 38        3.0    Benzyl Alcohol    30.0    Dipentene (KB-64) 10.0    Bentone (EW)      6.0    ______________________________________

An increase in conjugated terpene was generally associated with anincrease in stripping efficiency. Benzyl alcohol also plays an importantrole in obtaining stripping efficiency. Lower Kauri-Butanol ValueDipentene (KB value of 64, as opposed to 100) was inserted as a controlvariable to determine whether stripping activity was influenced by KB.Aliquots of Examples 13 and 14 were applied to the standardized 9"×12"panels. No measurable change in stripping time was observed.

EXAMPLE 15

This example was performed to determine what effect the inclusion ofwater would have on stripping efficiency. In this example 15, theinclusion of water caused the stripping time to be decreased but theoverall completeness of stripping (number of layers that the stripperlifted) was not affected.

    ______________________________________    Alpha-Terpinene   50.0    Chlorophyll MM    1.0    Bentone 38        3.0    Benzyl Alcohol    30.0    Water             3.0    Dipentene (KB-64) 10.0    Bentone(EW)       3.0    ______________________________________

EXAMPLES 16 and 17

These examples were performed to determine the effect that the inclusionof chlorophyll would have on the stripping efficiency of thecompositions of the present invention. Example 16 changed the componentorder in anticipation of a two component binary system of delivery.Aliquots of Examples 16 and 17 were applied to standard 9"×12" panelsand subjected to both direct sunlight and incident light in order toobserve the influence of Chlorophyll on the compositions. Both examplesperformed well, however Example 17 exhibited slightly reduced strippingtime in direct sunlight.

EXAMPLE 16

    ______________________________________    Alpha-Terpinene   30.0    Bentone 38        3.0    Chlorophyll MM    1.0    Benzyl Alcohol    40.0    Dipentene (KB-100)                      20.0    Bentone(EW)       6.0    ______________________________________

EXAMPLE 17

    ______________________________________    Alpha-Terpinene   30.0    Bentone 38        3.0    Benzyl Alcohol    40.0    Dipentene (KB-100)                      21.0    Bentone(EW)       6.0    ______________________________________

EXAMPLES 18-21

Examples 18-21 were prepared to examine the performance of the highermolecular weight monohydroxy alcohol alternatives to Benzyl alcohol.Aliquots from Examples 18-21 exhibited significant stripping efficiency,all compositions performed significantly less favorably than didcompositions prepared with a benzyl alcohol component.

EXAMPLE 18

    ______________________________________    Alpha-Terpinene   30.0    n-Octyl Alcohol   40.0    Bentone 38        3.0    Chlorophyll MM    1.0    Dipentene (KB-100)                      20.0    Bentone(EW)       6.0    ______________________________________

EXAMPLE 19

    ______________________________________    Alpha-Terpinene   30.0    n-Butyl Alcohol   40.0    Bentone 38        3.0    Chlorophyll MM    1.0    Dipentene (KB-100)                      20.0    Bentone(EW)       6.0    ______________________________________

EXAMPLE 20

    ______________________________________    Alpha-Terpinene   30.0    n-Octyl Alcohol   40.0    Bentone 38        3.0    Dipentene (KB-100)                      20.0    Bentone(EW)       6.0    ______________________________________

EXAMPLE 21

    ______________________________________    Alpha-Terpinene   30.0    n-Butyl Alcohol   40.0    Bentone 38        3.0    Dipentene (KB-100)                      21.0    Bentone(EW)       6.0    ______________________________________

EXAMPLE 22

Example 22 was prepared to determine the effect of the conjugatedpolyene, and in particular, the conjugated terpene compound on strippingefficiency. Peppermint oils (a terpene compound) was substituted for thealpha-terpinene previously used.

    ______________________________________    Peppermint Oils 30.0    Bentone 38      3.0    Benzyl Alcohol  40.0    Dipentene       21.0    Bentone(EW)     6.0    ______________________________________

Aliquots from Example 22 were applied to test panels to observe theefficacy of the composition without the presence of large quantities ofconjugated diene terpene (the dipentene did contain about 12% to about15% by weight conjugated terpenes which at least partially provideactivity in the instant compositions. We concluded that the presence ofconjugated diene is at least partially responsible for the enhancedstripping activity exhibited by the present invention.

EXAMPLES 23-44

These examples were prepared to determine the impact of terpene alcoholson the stripping efficiency of compositions according to the presentinvention. Terpene alcohols proved to be useful in compositionsaccording to the present invention. We note that the dipentene used inthese examples contained from 12% to about 15% by weight of conjugatedterpene compounds. Although these compositions were active and providedadequate stripping efficiency, the rather small amount of conjugatedterpenes (ranging from about 3-4% by weight with the exception ofexample 32, which contained about 30-31% by weight conjugated terpenes)did not provide the stripping efficiency of compositions containinglarger quantities of conjugated terpene compounds.

EXAMPLE 23

    ______________________________________           Dimethyl Octanol                      27.0           Bentone 38 3.0           Benzyl Alcohol                      40.0           Dipentene  24.0           Bentone(EW)                      6.0    ______________________________________

EXAMPLE 24

    ______________________________________           Dihydromyrcenol                      27.0           Bentone 38 3.0           Benzyl Alcohol                      40.0           Dipentene  24.0           Bentone(EW)                      6.0    ______________________________________

EXAMPLE 25

    ______________________________________           Dihydroterpineol                      27.0           Bentone 38 3.0           Benzyl Alcohol                      40.0           Dipentene  24.0           Bentone(EW)                      6.0    ______________________________________

EXAMPLE 26

    ______________________________________    Dihydrolinalool 27.0    Bentone 38      3.0    Benzyl Alcohol  40.0    Dipentene       24.0    Bentone(EW)     6.0    ______________________________________

EXAMPLE 27

    ______________________________________    Citronellol     27.0    Bentone 38      3.0    Benzyl Alcohol  40.0    Dipentene       24.0    Bentone(EW)     6.0    ______________________________________

EXAMPLE 28

    ______________________________________    Dihydrocarveol  27.0    Bentone 38      3.0    Benzyl Alcohol  40.0    Dipentene       24.0    Bentone(EW)     6.0    ______________________________________

EXAMPLE 29

    ______________________________________    Geraniol        27.0    Bentone 38      3.0    Benzyl Alcohol  40.0    Dipentene       24.0    Bentone(EW)     6.0    ______________________________________

EXAMPLE 30

    ______________________________________    Arbanol         27.0    Bentone 38      3.0    Benzyl Alcohol  40.0    Dipentene       24.0    Bentone(EW)     6.0    ______________________________________

EXAMPLE 31

    ______________________________________    95% Terpene Alcohol Solvents                          27.0    Bentone 38            3.0    Benzyl Alcohol        40.0    Dipentene             24.0    Bentone(EW)           6.0    ______________________________________

EXAMPLE 32

    ______________________________________    Myrcene         27.0    Bentone 38      3.0    Benzyl Alcohol  40.0    Dipentene       24.0    Bentone(EW)     6.0    ______________________________________

EXAMPLE 33

    ______________________________________    Solvent Alcohols, flash pt. 200                          27.0    Bentone 38            3.0    Benzyl Alcohol        40.0    Dipentene             24.0    Bentone(EW)           6.0    ______________________________________

EXAMPLE 34

    ______________________________________           Trans-2 Hexanol                      27.0           Bentone 38 3.0           Benzyl Alcohol                      40.0           Dipentene  24.0           Bentone(EW)                      6.0    ______________________________________

EXAMPLE 35

    ______________________________________           Trans-2-Hexanal                      27.0           Bentone 38 3.0           Benzyl Alcohol                      40.0           Dipentene  24.0           Bentone(EW)                      6.0    ______________________________________

EXAMPLE 36

    ______________________________________    Linalool        27.0    Bentone 38      3.0    Benzyl Alcohol  40.0    Dipentene       24.0    Bentone(EW)     6.0    ______________________________________

EXAMPLE 37

    ______________________________________    Nerol           27.0    Bentone 38      3.0    Benzyl Alcohol  40.0    Dipentene       24.0    Bentone(EW)     6.0    ______________________________________

EXAMPLE 38

    ______________________________________    Nopol           27.0    Bentone 38      3.0    Benzyl Alcohol  40.0    Dipentene       24.0    Bentone(EW)     6.0    ______________________________________

EXAMPLE 39

    ______________________________________    Menthol         27.0    Bentone 38      3.0    Benzyl Alcohol  40.0    Dipentene       24.0    Bentone(EW)     6.0    ______________________________________

EXAMPLE 40

    ______________________________________    3-Octanol       27.0    Bentone 38      3.0    Benzyl Alcohol  40.0    Dipentene       24.0    Bentone(EW)     6.0    ______________________________________

EXAMPLE 41

    ______________________________________    cis-2-Pinanol   27.0    Bentone 38      3.0    Benzyl Alcohol  40.0    Dipentene       24.0    Bentone(EW)     6.0    ______________________________________

EXAMPLE 42

    ______________________________________    Fernlol         27.0    Bentone 38      3.0    Benzyl Alcohol  40.0    Dipentene       24.0    Bentone(EW)     6.0    ______________________________________

EXAMPLE 43

    ______________________________________    Terpineol       27.0    Bentone 38      3.0    Benzyl Alcohol  40.0    Dipentene       24.0    Bentone(EW)     6.0    ______________________________________

EXAMPLE 44

    ______________________________________           Tetrahydrolinallol                      27.0           Bentone 38 3.0           Benzyl Alcohol                      40.0           Dipentene  24.0           Bentone(EW)                      6.0    ______________________________________

EXAMPLE 45

    ______________________________________    Tetrahydromyrcenol                      27.0    Bentone 38        3.0    Benzyl Alcohol    40.0    Dipentene         24.0    Bentone(EW)       6.0    ______________________________________

EXAMPLE 46

    ______________________________________    Tetralol        27.0    Bentone 38      3.0    Benzyl Alcohol  40.0    Dipentene       24.0    Bentone(EW)     6.0    ______________________________________

EXAMPLES 47 and 48

Examples 47-48 were prepared to determine the effect that the instantinvention would have on prior art compositions and in particular,compositions disclosed in U.S. Pat. No. 5,098,591, issued Mar. 24, 1992.In particular, Part A in Examples 47 and 48 was comprised of the presentinvention composition (except Part A of Example 48 contained nochlorophyll), whereas Part B of each example was made from componentsset forth in the '591 patent described above. Part B, as tested by anindependent laboratory, was shown to be one of the most activenon-toxic, biodegradable paint strippers available. In each of theseexamples, an equal amount of Part A was added to Part B and mixed byhand to produce a composition containing the same componentry of thepresent invention plus the componentry of the prior art. Part B of eachexample represented the prior art composition.

A mixture of Part A and Part B from each of examples 47 and 48 wasapplied to the standard 9" by 12" panels. Part B of each example waslikewise applied to the panels. The panels were then exposed to indirectlight. The mixtures of A and B in each example stripped through eightpaint layers (including a primer layer) within 2 and 1/2 hours, whereasthe part B product required about 24 hours.

EXAMPLE 47

    ______________________________________    PART A    Alpha-Terpinene   27.0    Bentone 38        3.0    Benzyl Alcohol    40.0    Chlorophyll MM    1.0    Dipentene         23.0    Bentone(EW)       6.0    PART B    Bentone(EW)       3.0    Ethanol           3.0    Water             10.0    PD-600 (Surfactant)                      2.0    Methyl Pyrollidone                      46.0    Propylene Carbonate                      29.0    Dipentene         7.0    ______________________________________

EXAMPLE 48

    ______________________________________    PART A    Alpha-Terpinene   27.0    Bentone 38        3.0    Benzyl Alcohol    40.0    Dipentene         24.0    Bentone(EW)       6.0    PART B    Bentone(EW)       3.0    Ethanol           3.0    Water             10.0    PD-600            2.0    Methyl Pyrollidone                      46.0    Propylene Carbonate                      29.0    Dipentene         7.0    ______________________________________

EXAMPLES 49-59

These 11 examples evidence the utility of the instant invention toremove and strip tough military coatings.

The general method employed in these examples is as follows: Certifiedtest panels conforming to Military Specification MIL-R-81294D, suppliedby a vendor recommended by the U.S. Navy were used to simulate aircraftsurfaces. The panels represent the two paint systems currently used onnaval aircraft. One panel consists of a polyamide/epoxy primer with anepoxy topcoat; the other the same primer with a polyurethane topcoat.

Compositions were applied by spatula to all test specimens on an areaabout 1 in.² in area, approximately 3 mm. (about 1/8") to about 6 mm.(about 1/4") thick. Test panels were then inserted into a chamber andsubjected to conditions being evaluated, i.e., radiant heat, U.V.,infra-red or combinations of those conditions for varying times. Timesof exposure were measured and noted.

Panels were also tested after exposure to measured irradiance from thefollowing light sources:

1000 Watt mercury vapor lamp;

250 Watt infra-red lamp;

250 Watt infra-red lamp with visible light blocked;

Available sunlight.

It was noted that all panels attained a surface temperature of at leastabout 42° C. (about 110° F.) using the varying forms of irradiation.

Additional artificial substrates of a non-military specification werealso utilized during evaluation and testing of the invention.

Complete lifting of all paint coatings with the primer from thesubstrate was considered a success.

The following paint stripper formulations were prepared according to thegeneral method described above for examples 1-60.

EXAMPLE 49

    ______________________________________    AMP (Aminomethylpropanol) 4%    SD-3                      5%    Alpha-terpinene (75%)     16%    Propylene Carbonate       15%    Benzyl Alcohol            50%    Bentone EW                10%    ______________________________________

EXAMPLE 50

    ______________________________________    AMP (95)                  2.5%    SD-3 (Organoclay Rheological)                              5%    Alpha-terpinene (75%)     29%    Dipentene                 15%    Benzyl Alcohol            39%    Bentone EW                9.5%    ______________________________________

EXAMPLE 51

    ______________________________________    Alpha-terpinene (75%)   23.1%    Dipentene               15.3%    Bentone 38              7.7%    Benzyl Alcohol          38.5%    Bentone EW              15.4%    ______________________________________

EXAMPLE 52

    ______________________________________    Alpha-terpinene (75%)      29%    Dipentene                  15%    Bentone 38                 5%    Benzyl Alcohol             37%    Bentone EW                 10%    DBSA (Dodecyl benzylsulfonic acid)                               4%    ______________________________________

EXAMPLE 53

    ______________________________________    Alpha-terpinene (75%)      29%    Dipentene                  15%    Bentone 38                 5%    Benzyl Alcohol             39%    Bentone EW                 10%    DBSA (Dodecyl benzylsulfonic acid)                               2%    ______________________________________

EXAMPLE 54

    ______________________________________    Alpha-terpinene (75%)   36.3%    Dipentene               11%    Bentone 38              12.9%    Benzyl Alcohol          19.5%    Bentone EW              20.2%    ______________________________________

EXAMPLE 55

    ______________________________________    Alpha-terpinene (75%)   36%    Dipentene               11%    Bentone 38              12.9%    Chlorophyll (MM)        0.5%    Benzyl Alcohol          19.3%    Bentone EW              20.2%    ______________________________________

EXAMPLE 56

    ______________________________________    Alpha-terpinene (75%)   36%    Dipentene               11%    Bentone 38              12.9%    Benzyl Alcohol          19.3%    Bentone EW              20.2%    ______________________________________

EXAMPLE 57

    ______________________________________    Alpha-terpinene (75%)    20%    Dipentene                6%    Bentone 38               7%    Benzyl Alcohol           40%    Bentone EW               27%    ______________________________________

EXAMPLE 58

    ______________________________________    Alpha-terpinene (75%)   33.3%    Dipentene               10.1%    Bentone 38              11.8%    Benzyl Alcohol          26.3%    Bentone EW              18.5%    ______________________________________

EXAMPLE 59

    ______________________________________    Alpha-terpinene (75%)   29%    Dipentene               17.8%    Bentone 38              9.6%    Alpha-terpineol         5%    Benzyl Alcohol          19.4%    Bentone EW              19.4%    ______________________________________

EXAMPLE 60

    ______________________________________    Alpha-terpinene (75%)   16.3%    Dipentene               4.9%    Bentone 38              5.8%    Benzyl Alcohol          40.3%    Bentone EW              32.7%    ______________________________________

Each of the stripping compositions from examples 49-60 completely liftedthe military coatings including the primer coating within a periodranging from about 45 minutes to about 90 minutes using each of themethods (UV, IR, radiant heat and sunlight). The formulations weremodified in order to determine workability of the compositions for useon vertical surfaces. The preferred method for stripping includes theuse of radiant heat where it is applicable. In certain cases the use oflight sources may be advantageous

It is to be understood that the examples and embodiments describedhereinabove are for the purposes of providing a description of thepresent invention by way of example and are not to be viewed as limitingthe present invention in any way. Various modifications or changes thatmay be made to that described hereinabove by those of ordinary skill inthe art are also contemplated by the present invention and are to beincluded within the spirit and purview of this application and thefollowing claims.

I claim:
 1. A composition for use in removing polymeric coatings fromflexible and inflexible surfaces consisting essentially of:a) about 10%to about 40% by weight of a conjugated terpene selected from the groupconsisting of alpha-terpinene, tagetone, terpinolene, isoterpinolene,allo-ocimene, myrcene, ocimenone and mixtures thereof; b) about 5% toabout 60% by weight of benzyl alcohol; c) 0% to about 70% by weight of aterpene compound other than a conjugated terpene selected from the groupconsisting of alpha-terpinene, tagetone, terpinolene, isoterpinolene,allo-ocimene, myrcene, ocimenone and mixtures thereof; d) 0% to about20% by weight of a surfactant; and e) about 0.05% to about 60% by weightof a rheological additive; f) about 2% to about 70% by weight a solventselected from the group consisting of N-methylpyrrolidone, ethylenecarbonate, propylene carbonate, butylene carbonate and mixtures,thereof; and g) an amine selected from the group consisting ofaminomethylpropanol, methylamine, dimethylamine, trimethylamine,ethylamine, diethylamine, triethylamine, propylamine, dipropylamine,tripropylamine, ethanolamine, triethanolamine and mixtures, thereof. 2.The composition according to claim 1 wherein said solvent isN-methylpyrrolidone.
 3. The composition according to claim 1 whereinsaid amine is aminomethylpropanol.
 4. The composition according to claim2 wherein said amine is aminomethylpropanol.
 5. The compositionaccording to claim 1 wherein said conjugated terpene is alpha-terpinene.6. The composition according to claim 4 wherein said conjugated terpeneis alpha-terpinene.
 7. The composition according to claim 6 wherein saidrheological additive is an organoclay rheological additive.
 8. Thecomposition according to claim 1 wherein said terpene compound (c) isdipentene.
 9. A method for removing a polymer coating from flexible andinflexible surfaces comprising applying a composition to said coatingand exposing said coating and said composition to heat energy, saidcomposition consisting essentially of:a) about 5% to about 90% by weightof a compound selected from the group consisting of conjugated terpenecompounds, beta-carotene and lycopene; b) about 10% to about 95% byweight of an alcohol according to the structure: ##STR3## where R₁ -R₅are H, C₁ -C₅ alkyl, NH₂, OH or OCH₃ ;with the proviso that when one ofR₁, R₂, R₃, R₄ or R₅ is NH₂, OH or OCH₃, the remainder of R₁, R₂, R₃, R₄or R₅ are H or C₁ -C₃ alkyl; c) 0% to about 70% by weight of a terpenecompound other than a conjugated terpene compound; d) 0% to about 20% byweight of a surfactant; and e) about 0.05% to about 60% by weight of arheological additive.
 10. The method according to claim 9 wherein eachof R1-R5 is H.
 11. The method according to claim 9 wherein said terpenecompound (c) comprises about 5% to about 50% by weight of saidcomposition and is selected from the group consisting of alphapinene,beta-pinene, delta-3-carene, citronellal, d-limonene, gamma-terpinene,dipentene, dihydromyrcenol, dihydroterpineol, dihydrolinalool,citronellol, dihydrocarveol, geraniol, arbanol, linalool, nerol,menthol, nopol, cis-2-pinanol, isoborneol, allcimenol, fernlol,farnesol, fenchol, nerolidol, piperitol, borneol, cineol, isobulegol,allcimenol, tetrahydrolinallol, tetrahydromyrcenol, tetralol, tagetol,allo-camenol, carveol, myrcenol and mixtures thereof.
 12. The methodaccording to claim 9 wherein said rheological additive is an organoclayrheological additive.
 13. The method according to claim 12 wherein saidheat energy is obtained from an infrared energy source.
 14. The methodaccording to claim 9 wherein said heat energy produces a temperature onthe surface of said coating of at least about 32° C.
 15. A method forremoving a polymer coating from flexible and inflexible surfacescomprising applying a composition to said coating and exposing saidcoating and said composition to heat energy, said composition consistingessentially of:a) about 10% to about 40% by weight of alpha-terpinene;b) about 5% to about 60% by weight of benzyl alcohol; c) 0% to about 70%by weight of a terpene compound other than alpha-terpinene; d) 0% toabout 20% by weight of a surfactant; and e) about 0.05% to about 60% byweight of a rheological additive.
 16. The method according to claim 15wherein said rheological additive is an organoclay rheological additive.17. The method according to claim 16 wherein said composition furthercomprises at least one solvent selected from the group consisting ofN-methylpyrrolidone, ethylene carbonate, propylene carbonate, butylenecarbonate, and mixtures thereof.
 18. The method according to claim 16wherein said solvent is N-methypyrrolidone.
 19. The method according toclaim 15 wherein said composition further comprises an amine selectedfrom the group consisting of aminomethylpropanol, methylamine,dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine,propylamine, dipropylamine, tripropylamine, ethanolamine,triethanolamine and mixtures, thereof.
 20. The method according to claim18 wherein said composition further comprises aminomethypropanol.